Hot journal alarm apparatus



May 20, 1947. G, Kr NEWELL HOT JOURNAL ALARM APPARATUS Filed March 30,1944 2 Sheets-Sheet 1 IN1/Emol:V GEORGE K. NEWELL.

ATTORNEY May 20, 1947.

G. K. NEWELL HOT JOURNAL ALARM APPARATUS Filed March 30, 1944 2Sheets-Sheet 2 Inf-76 x INVENTOR GEORGE K. NEWE'LL.

A TI'ORNE Y Patented May 20, 1947 UNITED STATES PATENT OFFICE HOTJOURNAL ALARM APPARATUS Application March 30, 1944, Serial No. 528,710

2 Claims.

This invention relates to hot journal alarm apparatus, that is,apparatus for giving a signal or an alarm whenever a bearing or journalapproaches an abnormally hot condition, and has particular relation tohot journal alarm apparatus for railway cars and trains.

The railroads have long sought a simple and inexpensive apparatus forapprising the engineer or crew of a train of the occurrence of a hot boxor hot axle journal on any of the cars of the train because hot boxesnot only damage the parts of the journals but may even result inbreakage of an axle and possible wreckage of the train due to derailmentof a car following breakage of the axle.

Various devices and apparatus have been proposed and employed for thepurpose of signaling the occurrence of a hot box on railway cars andtrains. Such devices and apparatus variously empl-oy different types ofthermal-responsive elements, such as fusible elements, bfi-metallicelements, gas-chambers, or thermo-couples.

It is an object of my present invention to provide a novel means forregistering the heat condition in a bearing or journal, such as the axlejournal of a railway car.

More particularly, it is an object of my invention to provide aWheatstone bridge arrangement including resistance elements ofrelatively high temperature coeii'cient of resistance; and to disposethe resistance elements in a manner to be responsive to the heatcondition of a plurality of journals, whereby to attain an unbalancedcondition of the bridge when an abnormal heat condition of one journalwith respect to the heat condition o-f another journal occurs.

It is another object of my invention to provide apparatus of the natureindicated in the foregoing objects characterized, however, in that someof the resistance elements of the Wheatstone bridge are exposed toambient temperature or heat conditions as distinguished from the heatcondition of a journal.

It is another object of my invention to provide apparatus of the natureindicated in the foregoing objects and further characterized by means,responsive to the travel of the car or train equipped with theapparatus, for intermittently rendering the apparatus eiective, therebyconserving the amount of electrical energy required to operate theapparatus.

The above objects, and other objects of my invention which will be madeapparent hereinafter, are attained by embodiments subsequently to bedescribed and illustrated in the accompanying drawings, wherein Fig. 1is a diagrammatic view showing one embodiment of my invention, asapplied to a pair of axle journals of a railway car truck.

Fig. 2 is a simplified schematic electrical wiring 2 diagramcorresponding to the apparatus shown in Fig. 1, and

Fig. 3 is a fragmental sectional view showing the form of cartridge orunit which may be employed to contain several of the resistance elementsof the Wheatstone bridge arrangement arranged for exposure to ambienttemperature. The device shown in Fig. 3 is to be considered as joined toapparatus shown in Fig. 1 at the line marked .r--x in substitution for apart of the apparatus shown in Fig. 1.

Description Referring to Fig. 1, there is shown a railway car wheel axleII broken at the middle and having similar roller bearing journalcasings I2 at opposite ends thereof. In each of the journal casings I2at a point outside the bearing races is a bore I3, in substantiallyparallel relation to the axle I I, forming a heat well, the heat inwhich is indicative of the heat in the journal. The bores I3 are linedwith suitable insulating material I4 to prevent grounding of parts of athermal-responsive device received therein and hereinafter referred toas a resistance cartridge or unit I5.

Each resistance cartridge or unit I5 comprises a screw plug Il that isscrewed into the outer threaded end 0f the bore I3 receiving it and isenclosed by an end cover I6 that is removably 30 secured to the journalcasing. Two concentric tubular members I8 and I9 of insulating materialare secured to screw plug I'l and extend generally in parallel relationto the axle I I. Wound on and secured to the outer tubular member I8 andthe inner tubular member I9 are resistance elements or coils ofresistance wire, such as iron wire, having a relatively high temperaturecoecient of resistance (.005 for iron wire).

The four resistance elements in the two cartridges are designatedrespectively as RI, R2, R3, and R4.

As shown in Fig. 1, resistance elements RI and R3 are disposed on theouter and inner tubular members I8 and I9 respectively of cartridge I545 associated with the left-hand journal. The resistance elements R2 andR4 are disposed on the outer and inner tubular members I8 and I9 of thecartridge I5 associated with the right-hand journal.

50 Resistance elements RI, R2, R3, and R4 are connected in a Wheatstonebridge arrangement as shown in Fig. 2. Suitable wires, hereinafteridentied, are connected to opposite ends of each resistance elementrespectively, making a total of 55 four Wires connected to eachcartridge unit I5. The screw plug I1 of each cartridge is provided withsuitable openings through which these lead wires extend, in insulatedrelation to the resistance elements.

ExternaI circuit connections are made to the resistance elements bymeans of suitable electric coupling devices or plugs 2l having contactprongs 22 that telescope in suitable sleeve contacts 23 carried in aninsulating bushing 24 supported in the end cover I6. Suitable means, notshown, but similar to that employed on radio tubes, is provided forinsuring proper connections through the coupling devices at all times.

As in the case of any Wheatstone bridge, a suitable source of current,illustrated as a storage battery 26, is provided. In the case of a trainof cars an individual battery 26 is provided for each car, which batterymay be the usual car lighting battery.

For the purpose of conserving the energy required from the battery 26, Ihave provided an intermittently operative switch device 21 formomentarlly connecting the battery 26 to the Wheatstone bridge circuitat intervals.

The switch device 21 may coirprise a separable casing 28 attached to apart of the car, such as the car truck, which is subject to pronouncedroad shock. As diagrammatically shown, switch device 21 may furthercomprise a contact arm 29 p-ivotcd at one end, as by a pin 3l, to a boss32 on the interior of the casing 28 and supported at the opposite end bya coil spring 33 interposed between the end thereof and the lower wallof the casing 29. For the purpose of imparting a pronounced inertiacharacteristic to the contact arm 29, a suitable weight 35 is securedthereto.

The contact arm 26 has an intermediate portion insulated entirely fromthe casing 28, which portion carries a contact 36 for cooperation with aspring-biased contact 31 supzorted in a recess 36 in the casing 28 atpoint below the arm 29.

The contact 31 is carried on the end of a pin 39 having a collar 49thereon which is guided in an insulating bushing 4l lining the recess38. The lower end of the pin 39 is gui-ded in an insulating bushing 42lining the lower portion of the recess 38 of reduced diameter.

An electrical connection is made to the pin 39 by means of a wire 43connected to a small metallic disk 44 at the base of the recess 38 andin insulated relation to the casing 28, a coil spring 45 beinginterposed between the disk 44 and the lower end of the pin 39. Aconstant electrical connection is thus made to the pin and contact 31,notwithstanding the oscillatory movement of the pin 39, without flexingthe wire 43 and causing breakage thereof.

An insulated wire 46 extends through a suitable opening or bushing inthe casing 28 and is connected to the intermediate or insulated portionof contact arm 29.

It will thus be seen that when the contact arm 29 is driven downwardlyby the inertia of the weight 35 in response to road shock, contacts 36and 31 become engaged and thereby complete a circuit from the wire 43 tothe 'wire 46. Upon termination of the shock which will be of momentar-yextent. the spring 33 restores the arm 29 upwardly and separates thecontacts 36 and 31. Assuming that a suiicient road shock is imparted tothe weight 35 each time a car wheel passes over a rail joint, it will beseen that the frequency of engagement of the contacts 36 and 31 will berelatively high but that the length of time that the contacts 36 and 31are engaged relative to the total travel time of the train will berelatively small.

Forthe purpose of registering the balanced or unbalanced condition ofthe Wheatstone bridge arrangement, I have provided a two-windingalternating-current type of relay 48. As diagrammatically shown in Fig.l, the relay 48 comprises two windings, designated a and b respectively,and two front contacts c and d respectively. The winding a is the pickupwinding and is connected into the Wheatstone bridge circuit in themanner hereinafter to be described so as to be responsive to apredetermined unbalanced voltage condition thereof in a manner toactuate the iront contacts c and d from their normally dropped-out oropen position to their picked-up o1' closed position.

The winding l2 of the relay 43 is a holding or stick winding, theenergizing circuit for which is established over the irontcontact cwhich serves as a self-holding contact.

A normally closed reset switch 49 which may be of the push-button typeas shown, is provided in the circuit of the holding winding b of relay43 and is effective when opened to interrupt the circuit for the holdingwinding and thereby effect restoration of the relay 48 to its droppedcutposition.

The character of the relay 48 is such that contacts c and d are actuatedto their picked-up positions in response to energization of the pickupwinding a by a current exceeding a certain value and flowing in eitherdirection through the winding, for a reason hereinafter explained.

The contact d of the relay 48 controls a circuit for energizing aplurality of signal devices, illustrated as an alarm bell 49, a signallamp 56, and a magnet valve 5I. The magnet valve 5l may be of anysuitable type effective upon energization of the winding thereof to ventiluid under pressure from a device to be controlled, such as the brakepipe 52 on the train, to initiate brake application.

As indicated in Fig. 1 and Fig. 2, the contact d of the relay 48 is alsoeffective to energize other signal devices, illustrated as an alarm bell49a and signal lamp 56a disposed in the cab of the locomotive or powercar of the train.

Operation In order to describe the operation of the apparatus let it beassumed that a train including a locomotive, car A, and car B, asindicated in Fig. l, is traveling along the road and that the axlejournals have attained their normal operating temperatures. Let it nowalso be assumed that the intermittently operative switch device 21 isoperated and that the contacts 36 and 31 thereof are engaged. In suchcase, the battery 26 is connected to the Wheatstone bridge circuit and aflow of current occurs therein. Referring to Fig. l the Wheatstonebridge circuit may be traced from the positive terminal of the battery26 by way of a wire 54, wire 43y contacts 31 and 36 of the switch device21, contact arm 29, wire 46, to a bus wire 55 local to car A, where thecircuit divides into two parallel branches; one of the branchesextending by way of a wire 6I, resistance element Rl, wire 62,resistance element R4, wire 63, to a bus wire 56 local to car A that isconnected by a branch wire 65 to the negative and grounded terminal ofthe battery 26, the other branch extending from the bus wire 55 by wayof a wire 66, resistance element R2, wire 61, resistance element R3, anda wire 68 to the bus wire 56, and thence by way of the branch wire 65 tothe negative terminal of the battery 26. This circuit will be morereadily apparent in Fig. 2.

If the respective temperatures of the two axle journals aresubstantially the same, as they will be if operating at their normaltemperatures, the Wheatstone bridge wil1 be in a balanced condition. Insuch case, therefore, no current or substantially no current will flowthrough the pickup winding a of the relay 48 because no unbalancedvoltage is impressed on the pick-up winding that is connected across thewires 62 and 61.

As long as both axle journals remain at normal operating temperature,the relay 48 will remain dropped-out notwithstanding the frequentestablishment of the flow of current in the Wheatstone bridge by theoperation of the switch device 21.

If, however, one of the axle journals such as the left-hand journal inFig. l, starts to heat-up and reaches or approaches a temperature whichmay cause damage to the parts of the journal, the increased resistanceof the resistance elements Rl and R3 produces an unbalanced voltagecondition in the Wheatstone bridge upon connection of the battery 26thereto by operation of the switch device 21. It will be apparent thatby reason of the arrangement of the two resistance elements Rl and R3 inthe Wheatstone bridge and their disposition in the same heat detectorcartridge I5, a maximum unbalance of the bridge circuit is attained fora given rise in temperature of the axle journal affected. In otherwords, by exposing two of the resistance elements, such as Rl and R3, tothe same variation of temperature or heat condition, twice the amount ofunbalanced voltage is created across the terminals of the pick-upwinding a of the relay 48 as would be the case if only one resistanceelement such as the resistance element RI were eiTected by theequivalent temperature or heat change. This specic arrangement isaccordingly one of the particular features of my invention by reason ofthe sensitivity it imparts in the apparatus to temperature changes inthe axle journals.

The resistance of the resistance elements RI, R2, R3, and R4 when coldis preferably of uniform value and is so selected, with respect to thevoltage of the battery 26 impressed on the Wheatstone bridge circuit, asto provide a suilicient voltage-drop across the pick-up winding a ofrelay 48 to cause actuation of the contacts of the relay to theirpicked-up position only after the temperature in one of the axlejournals rises a predetermined amount above the normal operatingtemperature thereof as exemplied by the temperature of the unaiectedjournal. The exact degree of temperature rise above normal operatingtemperature of the axle journal at which the pick-up of the relay 48 iseffected may be any desired amount dependent upon the degree of safetyfactor desired. It should be so selected, however, as to be sufiicientlybelow the danger point at which severe damage may occur so as to provideadequate time for a train to be brought to a stop and suitable measurestaken to restore the temperature of the affected journal to normal andto prevent recurrence of the abnormal heat condition.

Once the contacts of the relay 48 are picked-up, they are thereaftermaintained in their picked-up position by the action of the holdingwinding b, the energizing circuit for which is established upon closureof the contact c. The circuit for energizing the holding winding b ofrelay 48 may be traced from the positive terminal of the battery 26 byway of the Wire 54, a bus wire 51 local to car A, a wire 1| includingthe contact c of relay 48, holding winding b, and the reset switch 49min series relation therein, and bus Wire 56 and wire 65 to the negativeterminal of the battery 26.

Contact d of the relay 48 is effective, when closed, to establish acircuit for energizing and causing actuation of the alarm bell 49, thesignal lamp 58, and the magnet winding of the magnet valve 5| on car A,as well as the alarm bell 49a and the signal lamp 50a in the cab on thelocomotive. the positive terminal -of the battery 26 by way of the wire54, bus wire 51, branch wire 1|, a branch wire 13, contact d of relay48, a wire 14, thence in parallel through the operating winding of thealarm bell 49, signal lamp 58, and the magnet winding of the magnetvalve 5| to a wire 15, which is in turn connected to the negativeterminal of the battery 25 by way of the bus wire 56 and wire 65. Thiscircuit also extends from the contact d of relay 48 by way of the wire14, a branch wire 16 including an asymmetric device 16x, such as a drydisk or tube type of rectifier, to a train wire 11, thence to thelocomotive and by way of a branch wire 18, in parallel through theoperating winding of the alarm bell 49a and signal lamp 50a to a wire 19which is connected to the negative terminal of the battery 26 as througha ground connection in the manner shown. It will thus be seen that uponthe pick-up of the relay 48 due to an abnormal rise of temperature inone of the axle journals, various signal devices on the individual carare actuated as well as those on the locomotive.

As previously indicated, energization of the winding of the magnet valve5| causes a reduction of the pressure in the brake pipe 52 resulting inan automatic application of the brakes on the train, thereby forcing theengineer to shut off the propulsion power and bring the train to a stopat once. If desired, the magnet valve 5| may be omitted, in which casethe automatic application of the brakes on the train in response topick-up of the relay 48 is not effected.

The arrangement of the asymmetric devices 16x is such as to permit theHow of current from a battery on a car to the train wire 11 but toprevent the reverse flow of current from the train wire to the signaldevices on a car from the train wire. It will thus be apparent that whenthe train wire 11 is energized by flow of current therein due to pick-upof the relay 48 on one car, such as car A, the signal devices 49, 50,and 5| on another car, such as car B, are not affected because currentcannot flow from the train wire 11 past the rectifier or asymmetricdevice 16a: on car B to those signal devices on car B,

I have previously disclosed and claimed this general arrangement forcausing a signal to be simultaneously produced on a car having a hotjournal and on the locomotive while preventing the actuation of signaldevices on cars not having a hot journal in my prior copendingapplication, Serial No. 528,709, led March 30, 1944, and assigned to theassignee of the present application. I accordingly make no claim to thisfeature in the present application.

In order to cause termination of the audible and visible signals on thecars and on the locomotive, the engineer and crew of a train will notintentionally disregard the occurrence of a hot box condition on any carof the train since it is a clear indication of their neglect to take thenecessary steps to alleviate the condition. In the present instance, letit now be assumed that due to the automatic application of the brakesThis circuit may be traced from y effected by operation of the magnetvalve 5| or, in the absence of the magnet valve 5l, due to theapplication of the brakes on the train initiated by the engineer on thelocomotive, upon receipt of a signal, the train is brought to a stop andthe necessary measures taken to alleviate the hot box condition.

It is desirable that it be mandatory, on the part of the engineer orsome member of the train crew, to take some positive steps towardalleviation of the hot box condition in order to cause termination ofthe audible and visible signal on the car and on the locomotive. Such anarrangement is disclosed and claimed in my prior copending applicationabove mentioned. In the present application, I have indicated aso-called reset switch 49x in the circuit of the holding winding b ofthe relay 48. Although not s shown in the drawings, switch 49.7: ispreferably located at a point which cannot be reached unless a positivestep is taken toward alleviation of the hot box condition, such as onthe interior of the end cover I6 of the axle journal casing. I have, forsimplicity, not indicated such a location for the reset switch 49x, butit will be understood that in accordance with the principles taught inmy prior copending application above mentioned, such location of thereset switch 49a: may be selected.

It will be apparent, therefore, that in Order to operate the resetswitch 49a: to open position, it will be necessary to remove the endcover I6, thereby automatically insuring that a positive step will betaken toward alleviation of the hot box condition.

Upon opening of the reset switch 49:12, the holding winding b of therelay is deenergized and, in the absence of any energization of thepick-up winding o of the relay 48, as presently explained, the relaywill be restored to its dropped-out position. thereby interrupting thecircuit for energizing the signal devices on the cars on the locomotive.

It will be seen that with the train stopped, the switch 2l will remainin open position, thus disconnecting the battery 2E from the Wheatstonebridge circuit. Consequently there will be no voltage available topiek-up the relay 48. Consumption of energy from battery 26 will thus beconserved. operation of the reset switch 49x to its open positionresults in restoration of the relay 48 to its dropped-out position.

It should be apparent that by reason of the non-directionalcharacteristic of the pick-up winding of relay 48, the relay 48 will bepickedup in response to the occurrence of an abnormal heat condition ineithel` of the axle journals. In the case of an abnormal heat conditionoccurring in the right-hand journal, therefore, notwithstanding the factthat the polarity of the unbalanced voltage impressed on the pick-upwinding a of relay 48 will be reversed with respect to that which existsin the case of an abnormal heat condition occurring in the left-handaxle journal, relay 48 will be picked-up.

In Fig. l I have shown only one pair of axle journals, but it will beunderstood that the resistance elements in the heat detector cartridgesI5 of other pairs of axle journals associated with a common axle on thesame car are connected to the bus wires 55 and 5S in parallel relationto those shown in Fig. l. Thus, a single battery 26 may serve as acommon voltage source for a plurality of Wheatstone bridge circuits,subject to With the train stopped, therefore,

the control of a single intermittently operated switch device 21. Insuch case, however, the contacts d of the several relays 48 associatedwith each Wheatstone bridge respectively must of necessity be connectedin parallel if it is desired to employ only one set of signal devices,such as the alarm bell 49, signal lamp 50, and magnet valve 5 l, on eachcar. If desired, however, each Wheatstone bridge arrangement on each carmay have its own set of signal devices controlled by its correspondingrelay 48.

It is deemed unnecessary to describe in detail the schematic diagram ofthe equipment as shown in Fig. 2, since corresponding parts in Figs. land 2 are designated by the same reference numerals. Fig. 2 serves morereadily than does Fig. 1 to convey an understanding of the arrangementof the resistor elements Rl, R2, R3, and R4 in a Wheatstone bridgecircuit, as well as of the relative points of connection of the relay 48and the battery 26 to the Wheatstone bridge circuit.

Figure 3 In Fig. 3, I have indicated a modication of the arrangementshown in Fig. 1, characterized by a heat detector cartridge 15a providedin the place of the heat detector cartridge l5 associated with theright-hand axle journal in Fig. 1.

The cartridge I 5A is essentially the same in structure as the cartridgei5, except for a modified form of base ila substituted for the screwplug Il and an outer enclosure in the form of a tubular housing 14a ofinsulating material attached to the base. In order to expose the interorof the tubular housing I4a to the ambient temperature. the housing has aplurality of holes or openings therein.

The heat detector cartridge 15A may be disposed and mounted in anyconvenient location. In the case of a railway car, it may be disposedwithin the car body so as not to be exposed to extremely low temperatureduring cold weather, thereby preventing a premature pick-up of the relay48 due to the initial diierential in the resistance of the resistanceelements of the heat detector cartridge 15A with respect to theresistance of the resistance elements in the cartridge I5 associatedwith an axle journal at normal operating temperatures.

The arrangement employing the heat detector cartridge |5A exposed toambient temperature is not as desirable for railway car trucks as thetwo journal arrangement shown in Fig. 1 because it requires twice thenumber of heat detector cartridges as the arrangement shown in Fig. 1,two detector cartridges being required for each axle journal instead ofone as in Fig. 1.

The arrangement including the heat detector cartridge 15A may beemployed to advantage, however, in other situations where it is desiredto have an indication of abnormal heat condition in a single journal orsingle bearing of a particular machine, such as a large generator ormotor in an electrical power station.

There being no difference in th'e character of ne operation, whenemploying the cartridge I 5A, with respect to the operation previouslydescribed in connection with the embodiment shown in Fig. 1, no furtherdescription of this modication is deemed to be required.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1 Apparatus for registering the heat condition in a given zone, saidapparatus comprising a Wheatstone bridge circuit having a separateresistance element in each of the four legs thereof, two of saidresistance elements being exposed to the heat condition in the givenzone and the remaining two resistance elements being exposed to the heatcondition in a different zone, means for intermittently impressing avoltage on said bridge circuit, said resistance elements being soarranged and connected that an unbalanced voltage is produced in saidcircuit while said voltage is impressed thereon upon a variation in theheat condition in the said given zone with respect to the heat conditionin the said different zone, electrical relay means operativelyresponsive to th'e said unbalanced voltage when in excess of a certainvalue, means for maintaining said relay in its picked-up positionnotwithstanding cessation of the unbalanced voltage in said bridgecircuit, signal means controlled by said relay, and means for restoringsaid relay to its dropped-out position.

2. Apparatus for registering the heat condition in a given zone, saidapparatus comprising a Wheatstone bridge circuit having a separateresistance element in each of the four legs thereof, two of saidresistance elements being exposed to the heat condition in the givenzone and the remaining two resistance elements being exposed to the heatcondition in a different zone, means for intermittently impressing avoltage on said bridge circuit, said resistance elements being soarranged and connected that an unbalanced voltage is produced in saidcircuit while said voltage is impressed thereon, upon a, variation inthe heat condition in the said given zone with respect to the heatcondition in the said different zone, an electrical relay having apick-up winding and a holding winding, said pick-up winding beingenergized in response to a predetermined unbalanced voltage produced insaid bridge circuit to cause actuation of the relay from its dropped-outto its picked-up position, said holding winding of the relay beingenergized to maintain the relay picked-up in response to pick-up of saidrelay, signal means operated so long as said relay is picked-up, andmanually operated switch means for effecting deenergization of theholding Winding of the relay and the consequent restoration of the relayto its dropped-out position to terminate operation of the signal means.

GEORGE K. NEWELL.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,175,432 Garretson Mar. 14, 19161,267,757 Gibson May 28, 1918 2,060,215 Hopkins et al. Nov. 10, 19362,126,115 Jordi Aug. 9, 1938 2,240,595 White May 6, 1941 2,088,485Schoepf et al. 1- July 27, 1937 2,164,674 Ziegler July 4, 1939 2,240,595White May 6, 1941 FOREIGN PATENTS Number Country Date 539,543 GreatBritain Sept. 16, 1941 401,667 Germany Sept. 8, 1924

